Longevity-tools.com

Homocysteine in Plasma

Intermediate of methionine metabolism whose blood level reflects folate, vitamin B12, and vitamin B6 availability, kidney clearance, and genetics such as MTHFR variants.
Roche method sheet
Also known as:
P-homocysteineHCYP-HCYHCYST.

Homocysteine ranges

Interpret your result
Standard lab range (without folate supplementation): < 15 µmol/L
15
According to Peter Attia, Homocysteine should be below 9 µmol/L:
9
According to OptimalDX, Homocysteine should be between 5 and 7.2 µmol/L:
5
7.2
B12 deficiency was associated with Homocysteine above 15 µmol/L:
15
Optimal range
Optimal range for Homocysteine appears to be between 5 and 8 µmol/L:
2
5
8
12
25
Why this optimal range?
Preliminary range is based on functional health organizations including but not limited to those listed above.

What a low value may mean:

Common reasons for low Homocysteine:

  • homocysteine is a substrate for glutathione and cysteine synthesis, very low levels may limit these antioxidant and detoxification pathways. Low levels have also been associated with idiopathic peripheral neuropathy.

    ,

What a high value may mean:

Common reasons for high Homocysteine:

  • High homocysteine most often reflects insufficient folate, vitamin B12, or vitamin B6 — the main and usually correctable cause, including with vegetarian or vegan diets (lower B12).

    Other contributors: impaired kidney function (reduced clearance), hypothyroidism, MTHFR and related genetic variants (MTR, CBS), advancing age, smoking, alcohol, chronic stress, and certain medications (methotrexate, metformin, cholestyramine, antiepileptics). Markedly high levels suggest inherited homocystinuria.

    ,

Possible consequences from high Homocysteine:

  • Cardiovascular disease (Atherosclerosis, Heart attack, Stroke)
  • Neurodegenerative disorders (Alzheimer's, Parkinson's, Dementia),

How to lower Homocysteine:

  • B12, folate and vitamin B6 supplementation
    Consider the methylated versions of B12 and folate (methylcobalamin and methylfolate)

Images:

Homocysteine increases during aging

Homocysteine increases during aging

2,106 participants
Venezuelan adults older than 55 years; reference curves use the normative subgroup
Dataset: Maracaibo Aging Study
Cross-sectional population-based study
High Homocysteine was associated with substantial rise in all-cause mortality

High Homocysteine was associated with substantial rise in all-cause mortality

27,737 participants
Participants in 11 prospective cohorts from Asia, Europe and North America
Dose-response meta-analysis of prospective cohorts

Get the Full Picture of Vitamin B12 Status

Combines vitamin B12 related markers into the cB12 indicator, estimates body B12 stores, and provides a personalized supplementation plan.

View Full Analysis

100% free and private. Enter only the values you have.

About the site author

My personal mission is to extend human lifespan by collectively adding 1 million years to people's lives.

That’s why I made this site 100% free, no sign-up, no email. Just instant results.

Zsolt Szabo
Zsolt Szabo Founder, Longevity-tools.com
Precision health consultant for labs and clinics

Please send me relevant research and feedback.

Any feedback is welcome at .
I am particularly interested in research on biomarkers associated with all-cause mortality and on defining optimal reference ranges.